SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46ac43e60e6b7ed73cbe036d4789958d80fd176d78da939367e0a326d863d3e8' 
  AND token = 'K+DAkOugEaNBwbY48y+48RhQ1gCwlDalNpEFnwdcoWk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}